---
url: https://docs.youcan.shop/themes/liquid/overview.md
---
# Liquid

Liquid is the templating language YouCan themes are built with. It lets you mix static HTML with logic and store data, so a theme can render a different page for every product, collection, or cart without writing a line of application code.

```liquid
<h1>{{ product.name }}</h1>

{% if product.available %}
  <span>{{ product.price | money }}</span>
{% else %}
  <span>{{ 'product.sold_out' | t }}</span>
{% endif %}
```

## Building blocks

| | |
| --- | --- |
| **[Objects](/themes/objects/introduction)** | Store data you can output or loop over, like [`product`](/themes/objects/product) or [`cart`](/themes/objects/cart). |
| **Tags** | Logic that controls a template: conditionals (`if`, `unless`, `case`), loops (`for`), and helpers (`form`, `paginate`, `render`). Browse the full list under Developer Tools ▸ Liquid ▸ Tags in the sidebar. |
| **Filters** | Functions applied to a value with the pipe (`\|`) character, for formatting and transforming output, for example `{{ product.price \| money }}`. Browse the full list under Developer Tools ▸ Liquid ▸ Filters in the sidebar. |
| **[Basics](/themes/basics/introduction)** | The primitive types and operators Liquid expressions are built from. |

## Where Liquid runs

Liquid renders [layouts](/themes/layouts), [templates](/themes/templates/overview), [sections](/themes/sections/overview), and [snippets](/themes/snippets). Which objects are available depends on where you are: some, like `cart` and `settings`, are global; others, like `product`, only exist on the template they belong to. Each [template type](/themes/templates/overview#template-types) page documents the objects it receives.

## Errors

When a Liquid error occurs, YouCan replaces only the failed part of the page with an error message. The rest of the page is rendered.

* If a tag or an output fails at render time, the error message is shown in its place.
* If a section, snippet or app block cannot be parsed, the error message is shown instead of it. A section keeps its wrapper element, so you can still select it in the theme editor.
* If a layout or a JSON template has an error, the error message is shown instead of the page.

The message contains the file and the line number:

```
Liquid error (sections/featured-products.liquid line 12): at_least filter input should be a number
```

If a filter or a tag fails for a reason that is not in the theme, the message is `internal error`. App embeds are rendered in `<head>` and at the end of `<body>`, so a failed tag in an embed is not shown.

In the code editor, Liquid syntax errors are marked on their line while you type. You cannot save a section that has a syntax error.